package week02;

public class T018 {
	
	private static int[][] triangle = { // Mutable
            {75},
            {95, 64},
            {17, 47, 82},
            {18, 35, 87, 10},
            {20, 4, 82, 47, 65},
            {19, 1, 23, 75, 3, 34},
            {88, 2, 77, 73, 7, 63, 67},
            {99, 65, 4, 28, 6, 16, 70, 92},
            {41, 41, 26, 56, 83, 40, 80, 70, 33},
            {41, 48, 72, 33, 47, 32, 37, 16, 94, 29},
            {53, 71, 44, 65, 25, 43, 91, 52, 97, 51, 14},
            {70, 11, 33, 28, 77, 73, 17, 78, 39, 68, 17, 57},
            {91, 71, 52, 38, 17, 14, 91, 43, 58, 50, 27, 29, 48},
            {63, 66, 4, 68, 89, 53, 67, 30, 73, 16, 69, 87, 40, 31},
            {4, 62, 98, 27, 23, 9, 70, 98, 73, 93, 38, 53, 60, 4, 23},
    };
	
	//逆推，从下到上
	//精华：triangle[i][j]=triangle[i][j]+Math.max(triangle[i+1][j], triangle[i+1][j+1]);
//	public static void run() {
//		int row = triangle.length;
//		for(int i=row-2;i>=0;i--) {
//			int col = triangle[i].length;
//			for(int j=0;j<col;j++)
//			{
//				triangle[i][j]=triangle[i][j]+Math.max(triangle[i+1][j], triangle[i+1][j+1]);
//			}
//		}
//		System.out.println(triangle[0][0]);
//	}
	
	//顺推：从上到下
	public static void run() {
		int row= triangle.length;
		int max =0;
		for(int i=1;i<row;i++) {
			//单独处理边上的值
			int col = triangle[i].length-1;
			triangle[i][0]+=triangle[i-1][0];
			triangle[i][col]+=triangle[i-1][col-1];
			for(int j=1;j<col;j++) {
				triangle[i][j]+=Math.max(triangle[i-1][j-1],triangle[i-1][j]);
			}
		}
		int len=triangle[row-1].length;
		for(int i=0;i<triangle[row-1].length;i++) {
			if(triangle[row-1][i]>max) max=triangle[row-1][i];
		}
		System.out.println(max);
	}
	

	public static void main(String[] args) {
		run();
	}
}
